The present invention relates to a method for manufacturing a twisted yarn wherein a rotor is rotably supported on a machine frame and has a yarn guide channel that extends radially relative to the axis of rotation of the rotor over at least a portion of the diameter of the rotor, wherein a yarn exiting from the yarn guide channel is guided through a yarn guide tube to a means for centering located on an extension of the axis of rotation of the rotor whereby into the space above the rotor dissolved fiber material is introduced which is fed through the rotor. The present invention also relates to a device for performing the method as described above.
Such a method and a device for performing the method are, in principle, known from German Patent 37 21 364. In this known method the twisted yarn is manufactured with the aid of a spindle rotor and the yarn exiting from the yarn guide channel is guided under balloon formation to a centering point positioned on an extension of the hollow spindle axle. Into the space defined by the yarn balloon a flowable medium is introduced so as not disturb the yarn balloon. This is achieved by providing the spindle rotor with a plurality of guide vanes arranged in a spoke-like fashion wherein the yarn guide channel extends through one of these guide vanes. In the case of a two-for-one twisting spindle the flowable medium to be introduced into the space defined by the yarn balloon is conditioned air or a two-phase medium such as droplets suspended in air which are to impart a special effect on the yarn. It is also suggested that with this method fiber material can be introduced into the space defined by the yarn balloon.
It is an object of the present invention to provide a method of the aforementioned kind for manufacturing a twisted yarn from at least two yarn components in which method dissolved fiber material is being used and wherein in two subsequent method steps fibers are first generated in a spinning process and directly further processed to form a twisted yarn which is then removed from the device for performing the method.
In German Offenlegungsschrift 1 785 366, originated in 1972, a spinning method is disclosed which at this time was referred to as "element spinning" in which fiber material arranged in a fiber strand forms a rotating balloon in which the fiber strand is subjected to at least two twists per rotation of the balloon and the resulting yarn is removed from the device. The device for performing this known spinning method has a spinning chamber positioned on a spindle. Into the spinning chamber the fiber material is introduced through a fiber feed tube arranged coaxially to the spindle axle and a channel extending radially through the spindle rotor. Within the spinning chamber a collecting ring for the fiber material is provided in which the fiber material is again formed to a roving. The roving or fiber strand exiting from the stretching unit is guided through a channel positioned within the spindle axle. Within the channel the roving is subjected to a first twist. The roving leaves the channel in the radial direction in order to enter a yarn balloon surrounding and rotating about the spinning chamber where the roving is subjected to a second twist.
This principle is also the basis for German Patent Application 40 23 397, originated in 1992, in which again a method for spinning of fibers to yarn as well as a spinning device for performing the method are disclosed wherein the fiber material is guided to a spinning rotor and the yarn is removed by guiding it in the opposite rotational direction so as to form a rotating, coaxial arc about the spinning rotor. The device for performing this known spinning method comprises a spinning rotor supported on a two-for-one rotor which is rotatably supported in a stationary housing. The fiber exiting the spinning rotor is removed via a removal channel, positioned within the two-for-one twister and extending in an arc about the spinning rotor, in order to be guided to the common axis of the spinning rotor and the two-for-one rotor and is then guided upwardly through the drive device of the two-for-one rotor. This imparts a second twist to the fiber. The fiber material is introduced into the spinning rotor through an inlet channel within the two-for-one rotor whereby the inlet opening of the channel is arranged symmetrically to the axis of the two-for-one rotor and the exit opening of the channel is eccentrically positioned to this axis.
The East German Publication 88 001 shows a method for manufacturing a textile yarn which is comprised of at least two spun fibers. In this method two rotor spinning devices positioned atop one another are used whereby the fiber removal tube of the upper rotor spinning device is introduced into the rotor of the lower rotor spinning device and is arranged coaxially to the fiber removal tube of the lower rotor spinning device. The fiber produced within the upper rotor spinning device is combined with the fiber produced in the lower rotor spinning device and wound about it. A yarn balloon is not employed in this method.